refactor: replace lambdas with CKeybindManager::switchToWindow (#3229)

moves `switchToWindow` lambdas to a single private method
`CKeybindManager::switchToWindow()`.

fixes #3227, as a by-product of the mouse motion simulation at the end
of `CKeybindManager::switchToWindow()`.

src/managers/KeybindManager.hpp

@@ -91,6 +91,7 @@ class CKeybindManager {
     bool                      ensureMouseBindState();
 
     static bool               tryMoveFocusToMonitor(CMonitor* monitor);
+    static void               switchToWindow(CWindow* PWINDOWTOCHANGETO);
 
     // -------------- Dispatchers -------------- //
     static void     killActive(std::string);